Table 2.
Diagnostic performance of liver stiffness measurement (LSM) by transient elastography in respect to clinically significant portal hypertension (CSPH, defined as hepatic venous pressure gradient, HVPG ≥ 10 mmHg)
| Criterion to rule in: LSM ≥ 25 | Criterion to rule out: Plt ≥ 150 and LSM ≤ 15a | |
|---|---|---|
| Sensitivity (%) (95%CI) | 67.5 (50.9–81.4) | 100 (91.1–100)b |
| Specificity (%) (95%CI) | 88.9 (73.9–96.9) | 66.6 (49.0–81.4) |
| Positive predictive value, PPV (%) (95%CI) | 87.1 (70.2–96.4) | 76.9 (63.2–87.5) |
| Negative predictive value, NPV (%) (95%CI) | 71.1 (55.7–83.6) | 100 (85.8–100)b |
| Ruled in as CSPH | 29/76 | – |
| True positives (CSPH, adequately ruled in) | 25/40 | – |
| False positives (ruled in, but no CSPH) | 4/29 | – |
| “Missed” CSPH (CSPH, but not ruled in) | 15/40 | – |
| Ruled out as CSPH | – | 24/76 |
| True negatives (no CSPH, adequately ruled out) | – | 24/36 |
| False negatives (ruled out, but CSPH) | – | 0/24 |
| “Missed” non-CSPH (no CSPH, but not ruled out) | – | 12/36 |
| Patients adequately ruled in or ruled out | 25 + 24 = 49/76 (64.5%) | |
| Patients who could not be ruled in or ruled out | 27/76 (35.5%), 4 misclassified as CSPH | |
Data are shown for cutoff values as suggested by Pons et al. [5] to rule-in CSPH (LSM ≥ 25 kPa) and to rule it out—platelet (Plt) counts ≥ 150 × 109/L and LSM ≤ 15 kPa. Among the 76 included patients, 40 (event prevalence 52.6%) suffered CSPH
aThis diagnostic test has a reverse logic as compared to the test/criterion defined to rule-in CSPH: a “positive test” (high platelet counts combined with low LSM) here serves to detect a lack of CSPH. Therefore, its “target” is a “non-condition.” In this sense, reliable recognition of the target would actually result in high specificity and high PPV. In order to avoid confusion, data are presented in the same direction as for the rule-in test/criterion
bOne-sided 97.5% confidence interval